Combustor

ABSTRACT

A combustor includes a combustion chamber and a liner surrounding the combustion chamber. A ridge on top of the liner extends continuously around the liner. In alternate embodiments, a ridge extends continuously around the liner, and a groove extends continuously around the liner adjacent to the ridge, wherein both of the ridge and the groove are either substantially flat or curved.

FIELD OF THE INVENTION

The present invention generally involves a combustor. Specifically,various embodiments of the present invention include a combustor havinga liner with enhanced durability.

BACKGROUND OF THE INVENTION

Combustors are known in the art for igniting fuel with air to producecombustion gases having high temperature and pressure. For example, gasturbine systems typically include multiple combustors that mix acompressed working fluid from a compressor with fuel and ignite themixture to produce high temperature and pressure combustion gases. Thecombustion gases then flow to a turbine where they expand to producework.

Each combustor typically includes a liner that surrounds the combustionchamber to contain the working fluid and fuel during combustion. Thetemperatures associated with the combustion often exceed 3500° F., andthe liner typically has a maximum operating temperature on the order ofapproximately 1500° F. Therefore, various systems and methods have beendeveloped to cool the liner. For example, the working fluid may bedirected over the external surface of the liner prior to flow into thecombustion chamber to provide film or convective cooling to the liner.Alternately, or in addition, the thickness of the liner may be increasedor thermal barrier coatings may be applied to the inside of the liner toprotect the liner from excessive temperatures. Despite these and othermeasures, dynamic changes in pressure and power loads may cause plasticdeformation, bulging, or creep to occur in the liner over time,resulting in additional maintenance, repairs, and unplanned outages.Therefore, an improved liner design with enhanced stiffness, rigidity,and/or cooling characteristics would be desirable.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention are set forth below in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

One embodiment of the present invention is a combustor that includes acombustion chamber and a liner surrounding the combustion chamber. Aridge on top of the liner extends continuously around the liner.

Another embodiment of the present invention is a combustor that includesa combustion chamber and a liner surrounding the combustion chamber. Aridge extends continuously around the liner, and a groove extendscontinuously around the liner adjacent to the ridge, wherein both of theridge and the groove are either substantially flat or curved.

A still further embodiment of the present invention is a combustor thatincludes a combustion chamber and a liner surrounding the combustionchamber. A radius extends continuously around the liner, and asubstantially flat segment extends continuously around the liner andadjacent to the radius. The radius and the substantially flat segmentdefine an outer circumference of the liner. The substantially flatsegment has a first end and a second end, and the outer circumference ofthe liner at the first end is greater than the outer circumference ofthe liner at the second end.

Those of ordinary skill in the art will better appreciate the featuresand aspects of such embodiments, and others, upon review of thespecification.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, including referenceto the accompanying figures, in which:

FIG. 1 is a simplified cross-section of a combustor according to oneembodiment of the present invention;

FIG. 2 is a side plan view of a liner according to a first embodiment ofthe present invention;

FIG. 3 is a side plan view of a liner according to a second embodimentof the present invention;

FIG. 4 is an enlarged view of a portion of the liner shown in FIG. 2 or3;

FIG. 5 is a side plan view of a liner according to a third embodiment ofthe present invention;

FIG. 6 is a side plan view of a liner according to a fourth embodimentof the present invention;

FIG. 7 is an enlarged view of a portion of the liner shown in FIG. 5 or6;

FIG. 8 is a side plan view of a liner according to a fifth embodiment ofthe present invention;

FIG. 9 is a side plan view of a liner according to a sixth embodiment ofthe present invention;

FIG. 10 is an enlarged view of a portion of the liner shown in FIG. 8 or9;

FIG. 11 is a side plan view of a liner according to a seventh embodimentof the present invention;

FIG. 12 is a side plan view of a liner according to an eighth embodimentof the present invention; and

FIG. 13 is an enlarged view of a portion of the liner shown in FIG. 8 or9.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to present embodiments of theinvention, one or more examples of which are illustrated in theaccompanying drawings. The detailed description uses numerical andletter designations to refer to features in the drawings. Like orsimilar designations in the drawings and description have been used torefer to like or similar parts of the invention.

Each example is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that modifications and variations can be made in thepresent invention without departing from the scope or spirit thereof.For instance, features illustrated or described as part of oneembodiment may be used on another embodiment to yield a still furtherembodiment. Thus, it is intended that the present invention covers suchmodifications and variations as come within the scope of the appendedclaims and their equivalents.

Various embodiments of the present invention provide a combustor withany one of several improved liner designs that enhance the stiffnessand/or rigidity characteristics of the liner. For example, in particularembodiments, the liner may include one or more ridges and/or one or moregrooves that extend around the liner in a spiral or parallel pattern. Inother particular embodiments, the liner may include one or more radiiand substantially flat segments that extend around the liner in a spiralor parallel pattern. In each embodiment, the combination of ridges,grooves, radii, and/or substantially flat segments have been designed toimprove the liner's resistance to premature buckling, creep, ordeformation that may be caused over time by dynamic pressure and loadchanges. In addition, the various embodiments have been designed toenhance film or convective cooling of the outside of the liner withoutincreasing manufacturing costs or difficulty.

FIG. 1 shows a simplified cross-section of a combustor 10 according toone embodiment of the present invention. As shown, the combustor 10 mayinclude one or more nozzles 12 radially arranged in a top cap 14. Acasing 16 may surround the combustor 10 to contain the air or compressedworking fluid exiting the compressor (not shown). An end cap 18 and aliner 20 generally surround a combustion chamber 22 downstream of thenozzles 12. A flow sleeve 24 with flow holes 26 may surround the liner20 to define an annular passage 28 between the flow sleeve 24 and theliner 20. The compressed working fluid may pass through the flow holes26 in the flow sleeve 24 to flow along the outside of the liner 20 toprovide film or convective cooling to the liner 20. The compressedworking fluid then reverses direction to flow through the one or morenozzles 12 and into the combustion chamber 22 where it mixes with fueland ignites to produce combustion gases having a high temperature andpressure.

FIGS. 2 and 3 show side plan views of the liner 20 according to firstand second embodiments of the present invention. In each particularembodiment shown in FIGS. 2 and 3, a ridge 30 on top of the liner 20extends continuously around the circumference of the liner 20 tostrengthen the liner 20. The ridge 30 may extend axially along a portionor the entire length of the liner 20, or a plurality of the ridges 30may extend axially along some or all of the length of the liner 20. Asshown in FIG. 2, the ridge 30 may form a continuous substantiallyparallel spiral around the liner 20. Alternately, as shown in theembodiment illustrated in FIG. 3, the liner 20 may include a pluralityof the ridges 30, with the ridges 30 forming substantially parallelcircles or hoops around the circumference of the liner 20.

FIG. 4 provides an enlarged view of a portion of the liner 20 shown inFIG. 2 or 3. The ridge(s) 30 may be forged or cast with the liner 20 tofacilitate ease of manufacturing, or the ridge(s) 30 may be added to theliner 20 by welding and subsequent machining, if desired. The dimensionsand spacing of the ridge(s) 30 may be selected according to variousdesign considerations to optimize the strength, stiffness, and/orrigidity of the liner 20, as well as the cooling provided by theridge(s) 30. For example, the height 32 and width 34 of the ridge(s) 30,as well as the distance 36 between adjacent ridge(s) 30 spiraling aroundor encircling the liner 20, may be selected based on the thickness 38 ofthe liner 20. In particular embodiments, the height 32 and/or width 34of the ridge(s) 30 may be approximately 0.3-1.4 times the thickness 38of the liner 20, and the distance 36 between adjacent ridges 30 may beapproximately 8-45 times the thickness 38 of the liner 20.

As shown in FIG. 4, each ridge 30 may comprise a base 40 proximate tothe liner 20 and a distal end 42. The base 40 may include a radius 44along at least a portion of the base 40. As used herein, the term“radius” includes any curved surface that reduces flow resistance acrossthe outer surface of the liner 20. The length of the radius 44 may beselected based on the thickness 38 of the liner 20. For example, theradius 44 may have a curved length 49 of approximately 0.15-1 times thethickness 38 of the liner. The radius 44 may be forged or cast with theridge(s) 30 during manufacture of the liner 20 or may be addedseparately, such as through lap welding and machining to produce asmooth, curved surface between the ridge(s) 30 and the liner 20. Asshown in FIG. 4, the distal end 42 may also include a radius 46 and/orterminate at a point 48 along at least a portion of the distal end 42.

FIGS. 5 and 6 provide side plan views of the liner 20 according to thirdand fourth embodiments of the present invention. In each particularembodiment shown in FIGS. 5 and 6, the ridge 30 again extendscontinuously around the circumference of the liner 20; however, theridge 30 is substantially wider than in the embodiments shown in FIGS.2-4. In addition, the particular embodiments shown in FIGS. 5 and 6further include a groove 50 that extends continuously around the liner20 adjacent to the ridge 30. A radius 52 between the ridge 30 and thegroove 50 provides a smooth transition between the ridge 30 and thegroove 50. The ridge 30 and groove 50 may extend axially along a portionor the entire length of the liner 20, or a plurality of the ridges 30and/or the grooves 50 may extend axially along some or all of the lengthof the liner 20. As shown in FIG. 5, the ridge 30 and groove 50 may forma continuous substantially parallel spiral around the liner 20.Alternately, as shown in the embodiment illustrated in FIG. 6, the liner20 may include a plurality of the ridges 30 and grooves 50, with atleast one groove 50 between adjacent ridges 30. In this manner, theridges 30 and grooves 50 form substantially parallel circles or hoopsaround the circumference of the liner 20.

FIG. 7 provides an enlarged view of a portion of the liner 20 shown inFIG. 5 or 6. The ridge(s) 30, groove(s) 50, and radii 52 may be forgedor cast with the liner 20 to facilitate ease of manufacturing, or theliner 20 may be pressed or stamped to form the ridge(s) 30, groove(s)50, and radii 52, if desired. The dimensions and spacing of the ridge(s)30, groove(s) 50, and radii 52 may be selected according to variousdesign considerations to optimize the strength, stiffness, and/orrigidity of the liner 20, as well as the cooling provided by theridge(s) 30 and groove(s) 50. For example, the height 54 and width 56 ofthe ridge(s) 30 and/or the groove(s) 50 continuously spiraling around orencircling the liner 20 may be selected based on the thickness 38 of theliner 20. In particular embodiments, the height 54 of the ridge(s) 30and/or groove(s) 50 may be approximately 1.1-2.5 times the thickness 38of the liner 20, and the width 56 of the ridge(s) 30 and/or thegroove(s) 50 may be approximately 8-45 times the thickness 38 of theliner 20 for liner thicknesses greater than approximately 0.09 inchesand approximately 16-90 times the thickness 38 of the liner 20 for linerthicknesses less than approximately 0.09 inches. Similarly, the radius52 may have a curved length 58 of approximately 0.5-2.5 times thethickness 38 of the liner 20. The ridge(s) 30 and/or the groove(s) 50may be substantially flat with the same height 54 and width 56, althoughsuch is not limitation of the present invention unless specificallyrecited in the claims.

FIGS. 8 and 9 provide side plan views of the liner 20 according to fifthand sixth embodiments of the present invention. In each particularembodiment shown in FIGS. 8 and 9, the ridge 30 again extendscontinuously around the circumference of the liner 20; however, theridge 30 is curved with the convex surface facing outward. In addition,the particular embodiments shown in FIGS. 8 and 9 further include agroove 50 that extends continuously around the liner 20 adjacent to theridge 30. A smooth transition between the ridge 30 and the groove 50produces a wavy surface on the outside of the liner 20. The ridge 30 andgroove 50 may extend axially along a portion or the entire length of theliner 20, or a plurality of the ridges 30 and/or the grooves 50 mayextend axially along some or all of the length of the liner 20. As shownin FIG. 8, the ridge 30 and groove 50 may form a continuoussubstantially parallel spiral around the liner 20. Alternately, as shownin the embodiment illustrated in FIG. 9, the liner 20 may include aplurality of the ridges 30 and grooves 50, with at least one groove 50between adjacent ridges 30. In this manner, the ridges 30 and grooves 50form substantially parallel circles or hoops around the circumference ofthe liner 20.

FIG. 10 provides an enlarged view of a portion of the liner 20 shown inFIG. 8 or 9. The ridge(s) 30 and groove(s) 50 may be forged or cast withthe liner 20 to facilitate ease of manufacturing, or the liner 20 may bepressed or stamped to form the ridge(s) 30 and groove(s) 50, if desired.The dimensions and spacing of the ridge(s) 30 and groove(s) 50 may beselected according to various design considerations to optimize thestrength, stiffness, and/or rigidity of the liner 20, as well as thecooling provided by the ridge(s) 30 and groove(s) 50. For example, theheight 54 and width 56 of the ridge(s) 30 and/or the groove(s) 50continuously spiraling around or encircling the liner 20 may be selectedbased on the thickness 38 of the liner 20. In particular embodiments,the height 54 of the ridge(s) 30 and/or groove(s) 50 may beapproximately 1.1-5 times the thickness 38 of the liner 20, and thewidth 56 of the ridge(s) 30 and/or groove(s) 50 may be approximately8-45 times the thickness 38 of the liner 20 for liner thicknessesgreater than approximately 0.09 inches and approximately 16-90 times thethickness 38 of the liner 20 for liner thicknesses less thanapproximately 0.09 inches.

FIGS. 11 and 12 provide side plan views of the liner 20 according toseventh and eighth embodiments of the present invention. Each particularembodiment shown in FIGS. 11 and 12 may include a corrugated surface 60with a radius 62 and a substantially flat segment 64 adjacent to theradius 62. The radius 62 and segment 64 extend continuously around theliner 20 to define an outer circumference of the liner 20. The segment64 has a first end 66 and a second end 68, and the outer circumferenceof the liner 20 at the first end 66 is greater than the outercircumference of the liner 20 at the second end 68 to provide thecorrugated surface 60. The direction of the corrugated surface 60 mayvary according to particular embodiments. For example, in the embodimentshown in FIG. 11, the first end 66 is upstream from the second end 68,and in the embodiment shown in FIG. 12, the first and 66 is downstreamfrom the second end 68.

The radius 62 and segment 64 may extend axially along a portion or theentire length of the liner 20, or a plurality of the radii 62 and/or thesegments 64 may extend axially along some or all of the length of theliner 20. As shown in FIG. 11, the radius 62 and the segment 64 may forma continuous substantially parallel spiral around the liner 20.Alternately, as shown in the embodiment illustrated in FIG. 12, theliner 20 may include a plurality of the continuous radii 62 and segments64, with at least one segment 64 between adjacent radii 62. In thismanner, the radii 62 and segments 64 form substantially parallel circlesor hoops around the circumference of the liner 20.

FIG. 13 provides an enlarged view of a portion of the liner 20 shown inFIG. 11 or 12. The radii 62 and segments 64 may be forged or cast withthe liner 20 to facilitate ease of manufacturing, or the liner 20 may bepressed or stamped to form the radii 62 and segments 64, if desired. Thedimensions and spacing of the radii 62 and segments 64 may be selectedaccording to various design considerations to optimize the strength,stiffness, and/or rigidity of the liner 20, as well as the coolingprovided by the radii 62 and segments 64. For example, the slope 70 ofthe segments 64 may be approximately 2-8 degrees with respect to theaxis of the liner 20. The height 72 of the corrugated surface 60 and thedistance 74 between adjacent radii 62 or adjacent segments 64continuously spiraling around or encircling the liner 20 may be selectedbased on the thickness 38 of the liner 20. In particular embodiments,the height 72 of the corrugated surface 60 may be approximately 1.1-3.0times the thickness 38 of the liner 20. The distance 74 between adjacentradii 62 or adjacent segments 64 may be approximately 8-45 times thethickness 38 of the liner 20 for liner thicknesses greater thanapproximately 0.09 inches and approximately 16-90 times the thickness 38of the liner 20 for liner thicknesses less than approximately 0.09inches. Similarly, the radii 62 may have a curved length 76 ofapproximately 0.5-2.5 times the thickness 38 of the liner 20.

It is believed that the various embodiments described and illustrated inFIGS. 2-13 will provide increased stiffness and rigidity to the linerwithout increasing manufacturing difficulty or costs. In addition, theridges, grooves, radii, and or flat segments will function asturbulators to enhance film or convection cooling of the liner. As aresult, it is anticipated that the useful life of the liners may beextended, and maintenance, repairs, and/or unplanned outages may beproduced.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other and examples areintended to be within the scope of the claims if they include structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims.

1. A combustor comprising: a. a combustion chamber; b. a linersurrounding the combustion chamber; and c. a ridge on top of the linerand extending continuously around the liner.
 2. The combustor as inclaim 1, wherein the ridge forms a continuous spiral around the liner.3. The combustor as in claim 1, wherein the ridge comprises a baseproximate to the liner and further comprising a radius along at least aportion of the base.
 4. The combustor as in claim 1, wherein the ridgecomprises a distal end having a radius along at least a portion of thedistal end.
 5. The combustor as in claim 1, wherein the ridge comprisesa distal end terminating at a point along at least a portion of thedistal end.
 6. The combustor as in claim 1, further comprising aplurality of the ridges extending continuously around the liner.
 7. Acombustor comprising: a. a combustion chamber; b. a liner surroundingthe combustion chamber; c. a ridge extending continuously around theliner; and d. a groove extending continuously around the liner adjacentto the ridge, wherein both of the ridge and the groove are eithersubstantially flat or curved.
 8. The combustor as in claim 7, whereinthe ridge forms a continuous spiral around the liner.
 9. The combustoras in claim 7, further comprising a radius between the ridge and thegroove.
 10. The combustor as in claim 7, wherein the ridge isapproximately the same width as the groove.
 11. The combustor as inclaim 7, further comprising a plurality of the ridges and a plurality ofthe grooves extending continuously around the liner.
 12. The combustoras in claim 11, wherein the plurality of ridges are substantiallyparallel to the plurality of grooves.
 13. The combustor as in claim 11,further comprising a radius between each ridge and each groove.
 14. Thecombustor as in claim 11, wherein each ridge is approximately the samewidth as each groove.
 15. A combustor comprising: a. a combustionchamber; b. a liner surrounding the combustion chamber; c. a radiusextending continuously around the liner; and d. a substantially flatsegment extending continuously around the liner and adjacent to theradius; e. wherein the radius and the substantially flat segment definean outer circumference of the liner; f. wherein the substantially flatsegment has a first end and a second end, and the outer circumference ofthe liner at the first end is greater than the outer circumference ofthe liner at the second end.
 16. The combustor as in claim 15, whereinthe radius forms a continuous spiral around the liner.
 17. The combustoras in claim 15, wherein the first end is upstream of the second end. 18.The combustor as in claim 15, further comprising a plurality of radiicontinuously extending around the liner and a plurality of thesubstantially flat segments extending continuously around the linerwherein at least one substantially flat segment is between adjacentradii.
 19. The combustor as in claim 18, wherein the first end of eachof the plurality of substantially flat segments is downstream of thesecond end of each of the substantially flat segments.